The framing of a residential house with a pitched roof presents several problems well known to carpenters. One of these problems occurs in framing the end or gable of a pitched roof where vertical studs extend upwardly from a horizontal sill plate to the inclined rafter boards. Before assembling the studs with the sill and the rafters, both the sill and the rafters must be marked with lines indicating where each stud must be nailed in order for the stud to be perfectly plumb in its attachment between the sill and the rafter.
To accomplish this measuring and marking task in the past, a carpenter might use a common tape measure or perhaps a layout tool, or layout stick as it is commonly called, such as disclosed in the U.S. Pat. No. 3,169,320 to Currie. The layout tool of this patent has an elongated flat header plate and a plurality of shorter, flat branch plates. The branch plates are integral with the header plate, are spaced therealong, and extend outwardly from the header plate at right angles thereto. The discloses branch plates are at various spacings, specifically sixteen inches, twenty-four inches, thirty-two inches, and forty-eight inches from the endmost branch plate.
More commonly, the layout stick that is commercially available and used by many carpenters has these branch plates equally spaced along the header plate on either sixteen inch centers or twenty-four inch centers since these are the most common spacings of studs in residential construction. In any case, the branch plates of known layout sticks are integral with and in fixed space relation along the header plate.
In use of this well known layout stick, the carpenter first places the stick on the sill and marks it with lines indicating where the studs are to be nailed. Insofar as the rafters are concerned, however, the tool loses its utility since the stud marks on the rafter cannot be spaced the same distance apart as the marks on the sill. As will be understood, because of the rise of the roof, the spacing between adjacent studs as measured along the rafter, i.e. the hypotenuse of the triangle, will be slightly greater than the spacing between adjacent studs as measured along the sill, i.e. the base of the triangle. For example, if the studs are spaced along the sill on sixteen inch centers, and if for example the rise of the roof is three inches, the studs must be spaced along the rafter on sixteen and one eighth inch centers. The carpenter must therefor calculate this difference and then use another tool, i.e., a tape measure, to mark the rafters. Apart from the inconvenience, this procedure is prone to error in having to make a calculation after marking the sill and then in having to use a different tool to mark the rafters.